diff options
Diffstat (limited to 'nixos/modules/system/boot/stage-1.nix')
| -rw-r--r-- | nixos/modules/system/boot/stage-1.nix | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/nixos/modules/system/boot/stage-1.nix b/nixos/modules/system/boot/stage-1.nix new file mode 100644 index 000000000000..3836d639513e --- /dev/null +++ b/nixos/modules/system/boot/stage-1.nix @@ -0,0 +1,343 @@ +# This module builds the initial ramdisk, which contains an init +# script that performs the first stage of booting the system: it loads +# the modules necessary to mount the root file system, then calls the +# init in the root file system to start the second boot stage. + +{ config, pkgs, ... }: + +with pkgs.lib; + +let + + udev = config.systemd.package; + + kernelPackages = config.boot.kernelPackages; + modulesTree = config.system.modulesTree; + + + # Determine the set of modules that we need to mount the root FS. + modulesClosure = pkgs.makeModulesClosure { + rootModules = config.boot.initrd.availableKernelModules ++ config.boot.initrd.kernelModules; + kernel = modulesTree; + allowMissing = true; + }; + + + needsCifsUtils = kernelPackages.kernel ? features + && kernelPackages.kernel.features ? needsCifsUtils + && kernelPackages.kernel.features.needsCifsUtils + && any (fs: fs.fsType == "cifs") fileSystems; + + busybox = + if needsCifsUtils + then pkgs.busybox.override { + extraConfig = '' + CONFIG_FEATURE_MOUNT_CIFS n + CONFIG_FEATURE_MOUNT_HELPERS y + ''; + } + else pkgs.busybox; + + + # Some additional utilities needed in stage 1, like mount, lvm, fsck + # etc. We don't want to bring in all of those packages, so we just + # copy what we need. Instead of using statically linked binaries, + # we just copy what we need from Glibc and use patchelf to make it + # work. + extraUtils = pkgs.runCommand "extra-utils" + { buildInputs = [pkgs.nukeReferences]; + allowedReferences = [ "out" ]; # prevent accidents like glibc being included in the initrd + doublePatchelf = pkgs.stdenv.isArm; + } + '' + mkdir -p $out/bin $out/lib + + # Copy what we need from Glibc. + cp -pv ${pkgs.glibc}/lib/ld*.so.? $out/lib + cp -pv ${pkgs.glibc}/lib/libc.so.* $out/lib + cp -pv ${pkgs.glibc}/lib/libm.so.* $out/lib + cp -pv ${pkgs.glibc}/lib/libpthread.so.* $out/lib + cp -pv ${pkgs.glibc}/lib/librt.so.* $out/lib + cp -pv ${pkgs.glibc}/lib/libdl.so.* $out/lib + cp -pv ${pkgs.gcc.gcc}/lib*/libgcc_s.so.* $out/lib + + # Copy BusyBox. + cp -rvd ${busybox}/{bin,sbin} $out/ + chmod -R u+w $out + + # Copy some utillinux stuff. + cp -v ${pkgs.utillinux}/sbin/blkid $out/bin + cp -pdv ${pkgs.utillinux}/lib/libblkid*.so.* $out/lib + cp -pdv ${pkgs.utillinux}/lib/libuuid*.so.* $out/lib + + # Copy dmsetup and lvm. + cp -v ${pkgs.lvm2}/sbin/dmsetup $out/bin/dmsetup + cp -v ${pkgs.lvm2}/sbin/lvm $out/bin/lvm + cp -v ${pkgs.lvm2}/lib/libdevmapper.so.*.* $out/lib + cp -v ${pkgs.systemd}/lib/libsystemd-daemon.so.* $out/lib + + # Add RAID mdadm tool. + cp -v ${pkgs.mdadm}/sbin/mdadm $out/bin/mdadm + + # Copy udev. + cp -v ${udev}/lib/systemd/systemd-udevd ${udev}/bin/udevadm $out/bin + cp -v ${udev}/lib/udev/*_id $out/bin + cp -pdv ${udev}/lib/libudev.so.* $out/lib + cp -v ${pkgs.kmod}/lib/libkmod.so.* $out/lib + cp -v ${pkgs.acl}/lib/libacl.so.* $out/lib + cp -v ${pkgs.attr}/lib/libattr.so.* $out/lib + + # Copy modprobe. + cp -v ${pkgs.kmod}/bin/kmod $out/bin/ + ln -s kmod $out/bin/modprobe + + # Maybe copy cifs utils + ${optionalString needsCifsUtils '' + cp -v ${pkgs.cifs_utils}/sbin/mount.cifs $out/bin + ''} + + ${config.boot.initrd.extraUtilsCommands} + + # Strip binaries further than normal. + chmod -R u+w $out + stripDirs "lib bin" "-s" + + # Run patchelf to make the programs refer to the copied libraries. + for i in $out/bin/* $out/lib/*; do if ! test -L $i; then nuke-refs $i; fi; done + + for i in $out/bin/*; do + if ! test -L $i; then + echo "patching $i..." + patchelf --set-interpreter $out/lib/ld*.so.? --set-rpath $out/lib $i || true + if [ -n "$doublePatchelf" ]; then + patchelf --set-interpreter $out/lib/ld*.so.? --set-rpath $out/lib $i || true + fi + fi + done + + # Make sure that the patchelf'ed binaries still work. + echo "testing patched programs..." + $out/bin/ash -c 'echo hello world' | grep "hello world" + export LD_LIBRARY_PATH=$out/lib + $out/bin/mount --help 2>&1 | grep "BusyBox" + $out/bin/udevadm --version + $out/bin/dmsetup --version 2>&1 | tee -a log | grep "version:" + LVM_SYSTEM_DIR=$out $out/bin/lvm version 2>&1 | tee -a log | grep "LVM" + $out/bin/mdadm --version + + ${config.boot.initrd.extraUtilsCommandsTest} + ''; # */ + + + # The initrd only has to mount / or any FS marked as necessary for + # booting (such as the FS containing /nix/store, or an FS needed for + # mounting /, like / on a loopback). + fileSystems = filter + (fs: fs.neededForBoot || elem fs.mountPoint [ "/" "/nix" "/nix/store" "/var" "/var/log" "/var/lib" "/etc" ]) + (attrValues config.fileSystems); + + + udevRules = pkgs.stdenv.mkDerivation { + name = "udev-rules"; + buildCommand = '' + ensureDir $out + + echo 'ENV{LD_LIBRARY_PATH}="${extraUtils}/lib"' > $out/00-env.rules + + cp -v ${udev}/lib/udev/rules.d/60-cdrom_id.rules $out/ + cp -v ${udev}/lib/udev/rules.d/60-persistent-storage.rules $out/ + cp -v ${udev}/lib/udev/rules.d/80-drivers.rules $out/ + cp -v ${pkgs.lvm2}/lib/udev/rules.d/*.rules $out/ + cp -v ${pkgs.mdadm}/lib/udev/rules.d/*.rules $out/ + + for i in $out/*.rules; do + substituteInPlace $i \ + --replace ata_id ${extraUtils}/bin/ata_id \ + --replace scsi_id ${extraUtils}/bin/scsi_id \ + --replace cdrom_id ${extraUtils}/bin/cdrom_id \ + --replace ${pkgs.utillinux}/sbin/blkid ${extraUtils}/bin/blkid \ + --replace /sbin/blkid ${extraUtils}/bin/blkid \ + --replace ${pkgs.lvm2}/sbin ${extraUtils}/bin \ + --replace /sbin/mdadm ${extraUtils}/bin/mdadm + done + + # Work around a bug in QEMU, which doesn't implement the "READ + # DISC INFORMATION" SCSI command: + # https://bugzilla.redhat.com/show_bug.cgi?id=609049 + # As a result, `cdrom_id' doesn't print + # ID_CDROM_MEDIA_TRACK_COUNT_DATA, which in turn prevents the + # /dev/disk/by-label symlinks from being created. We need these + # in the NixOS installation CD, so use ID_CDROM_MEDIA in the + # corresponding udev rules for now. This was the behaviour in + # udev <= 154. See also + # http://www.spinics.net/lists/hotplug/msg03935.html + substituteInPlace $out/60-persistent-storage.rules \ + --replace ID_CDROM_MEDIA_TRACK_COUNT_DATA ID_CDROM_MEDIA + ''; # */ + }; + + + # The binary keymap for busybox to load at boot. + busyboxKeymap = pkgs.runCommand "boottime-keymap" + { preferLocalBuild = true; } + '' + ${pkgs.kbd}/bin/loadkeys -qb "${config.i18n.consoleKeyMap}" > $out || + ${pkgs.kbd}/bin/loadkeys -qbu "${config.i18n.consoleKeyMap}" > $out + ''; + + + # The init script of boot stage 1 (loading kernel modules for + # mounting the root FS). + bootStage1 = pkgs.substituteAll { + src = ./stage-1-init.sh; + + shell = "${extraUtils}/bin/ash"; + + isExecutable = true; + + inherit udevRules extraUtils modulesClosure busyboxKeymap; + + inherit (config.boot) resumeDevice devSize runSize; + + inherit (config.boot.initrd) checkJournalingFS + preLVMCommands postDeviceCommands postMountCommands kernelModules; + + fsInfo = + let f = fs: [ fs.mountPoint (if fs.device != null then fs.device else "/dev/disk/by-label/${fs.label}") fs.fsType fs.options ]; + in pkgs.writeText "initrd-fsinfo" (concatStringsSep "\n" (concatMap f fileSystems)); + }; + + + # The closure of the init script of boot stage 1 is what we put in + # the initial RAM disk. + initialRamdisk = pkgs.makeInitrd { + inherit (config.boot.initrd) compressor; + + contents = + [ { object = bootStage1; + symlink = "/init"; + } + { object = pkgs.writeText "mdadm.conf" config.boot.initrd.mdadmConf; + symlink = "/etc/mdadm.conf"; + } + ]; + }; + +in + +{ + options = { + + boot.resumeDevice = mkOption { + default = ""; + example = "0:0"; + description = " + Device for manual resume attempt during boot. Looks like + major:minor. ls -l /dev/SWAP_PARTION shows them. + "; + }; + + boot.initrd.checkJournalingFS = mkOption { + default = true; + type = types.bool; + description = '' + Whether to run fsck on journaling filesystems such as ext3. + ''; + }; + + boot.initrd.mdadmConf = mkOption { + default = ""; + type = with types; string; + description = '' + Contents of /etc/mdadm.conf at initrd. + ''; + }; + + boot.initrd.preLVMCommands = mkOption { + default = ""; + type = with types; string; + description = '' + Shell commands to be executed immediately before lvm discovery. + ''; + }; + + boot.initrd.postDeviceCommands = mkOption { + default = ""; + type = with types; string; + description = '' + Shell commands to be executed immediately after stage 1 of the + boot has loaded kernel modules and created device nodes in + /dev. + ''; + }; + + boot.initrd.postMountCommands = mkOption { + default = ""; + type = with types; string; + description = '' + Shell commands to be executed immediately after the stage 1 + filesystems have been mounted. + ''; + }; + + boot.initrd.extraUtilsCommands = mkOption { + internal = true; + default = ""; + type = with types; string; + description = '' + Shell commands to be executed in the builder of the + extra-utils derivation. This can be used to provide + additional utilities in the initial ramdisk. + ''; + }; + + boot.initrd.extraUtilsCommandsTest = mkOption { + internal = true; + default = ""; + type = with types; string; + description = '' + Shell commands to be executed in the builder of the + extra-utils derivation after patchelf has done its + job. This can be used to test additional utilities + copied in extraUtilsCommands. + ''; + }; + + boot.initrd.compressor = mkOption { + default = "gzip -9"; + + type = types.string; + + description = "The compressor to use on the initrd"; + + example = "xz"; + }; + + fileSystems = mkOption { + options.neededForBoot = mkOption { + default = false; + type = types.bool; + description = '' + If set, this file system will be mounted in the initial + ramdisk. By default, this applies to the root file system + and to the file system containing + <filename>/nix/store</filename>. + ''; + }; + }; + + }; + + config = { + + system.build.bootStage1 = bootStage1; + system.build.initialRamdisk = initialRamdisk; + system.build.extraUtils = extraUtils; + + system.requiredKernelConfig = with config.lib.kernelConfig; [ + (isYes "TMPFS") + (isYes "BLK_DEV_INITRD") + ]; + + }; +} |